Coordination compounds of methazolamide. Synthesis, spectroscopic studies and crystal structures of [M(Methazolamidato) 2(py) 2(OH 2) 2] (M  Co II, Ni II and Cu II)

Abstract

The synthesis and X-ray crystallographic characterization of three monomeric transition-metal coordination compounds with the ligand methazolamide {[N(4-methyl-2- sulphamoyl-Δ 21̄,3,4-thiodiazolin-5-ylidene)],acetamide} (abbreviated as Hmacm) are described, via [M(macm) 2(py) 2(OH 2) 2] [M  Co( 1), Ni( 2) and Cu( 3)]. In all the compounds the metal ion, lying on the centre of symmetry, is surrounded by two sulphonamidato nitrogen atoms and two pyridine nitrogen atoms in equatorial sites and two oxygen water molecules in axial positions. The coordination geometry of the metal is an almost regular octahedron around the cobalt(II) and nickel(II) ions. In contrast, the copper(II) ion has a significantly elongated octahedral geometry in the direction of the water molecules. Characterization of the compounds both in the solid state and in DMSO and DMFA solution has been carried out by IR, ligand-field spectroscopic data, magnetic susceptibilities, EPR, molar conductivities, 1H and 13C NMR.